## Probability Son, Father and Grandfather have same birthday.

Here is a quick request for comments for Probability 1 students. Here are two answers saying that the probability that a grandfather, father and son are all born on the same day.

https://www.mirror.co.uk/news/uk-news/baby-boy-born-same-date-13416140

https://www.bbc.co.uk/news/world-us-canada-41406855#

The first answer is sort of wrong because it assumes you specify in advance date of birth. The second answer is right because we assume in advance we are given three generations and we assume we deal with a first born son.

Please leave comments below and will forward them on to BBC.

## Some Mathematical Notation

Because I heard a few students had not come across some mathematical notation. Here is a quick introduction to a few mathematical terms.

## Robbins-Munro

We review the proof by Robbins and Munro for finding fixed points. Stochastic gradient descent, Q-learning and a bunch of other stochastic algorithms can be seen as variants of this basic algorithm. We review the basic ingredients of the original proof.